The three-year-old colt is one of a number of well-performed horses who have been transferred from Darren Weir to other trainers in recent days as Weir fights for his career after being charged with offences relating to illegal electronic devices found in his stable.
Extra Brut, who was scratched from last Saturday's Manfred Stakes at Caulfield, instead contested an 800m-barrier trial on Monday for his new co-trainers Ciaron Maher and David Eustace and finished fifth with Walker aboard.
He was due to ride Extra Brut in a race for the first time in last Saturday's Manfred Stakes.
“Extra Brut trialled really nice this morning,” Walker told broadcaster Racing.com after riding one of three winners at the Sale race meeting on Monday.
“He's an outstanding colt and a very classy colt.
“I know he's won over a mile-and-a-half. It was only a half-mile (800m) this morning and he really, really impressed me.”
Extra Brut has been nominated for Saturday's Group Two Autumn Stakes (1400m) at Caulfield but Maher has indicated on Melbourne radio the following week's C S Hayes Stakes (1400m) at Flemington is his plan.
Extra Brut is then expected to head towards the Group One Australian Guineas (1600m) on March 2 at Flemington.